Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds meaningful context about report contents and as-of/age-based selection, but it does not mention output shape, pagination, or Pro-access implications beyond the cryptic 'Pro' note.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The core description is one dense, front-loaded sentence that conveys the report's scope efficiently. The final 'Pro; deposit_balance is free' is a bit cryptic and could be clearer, but it does not add significant bulk.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only report with three optional, fully documented parameters and no output schema, the description covers the essential content and selection behavior. It lacks a clear mention of the return format, but the listed output sections are likely sufficient for an agent to invoke it.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3, but the description maps all three parameters to report sections: 'at a date' maps to as_of, 'oldest holdings' to limit, and 'older than N days with nothing applied' to older_than_days. This helps an agent connect parameter values to the resulting report without opening the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description specifies exactly what is reported—held per currency, received, applied and refunded, oldest holdings, and stale unapplied deposits—so an agent knows this is a deposit-book report. It does not use an explicit verb like 'generates' and only hints at sibling differentiation via 'deposit_balance is free,' so it falls just short of a 5.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no statement of when to choose deposits_report over deposit_balance, deposit_list, or deposit_statement_text. The 'Pro; deposit_balance is free' note implies a pricing/alternative relationship, but it does not explain when one should be selected instead of the other.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.